#region Using Directives and Copyright Notice

// Copyright (c) 2007-2010, Computer Consultancy Pty Ltd
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//     * Neither the name of the Computer Consultancy Pty Ltd nor the
//       names of its contributors may be used to endorse or promote products
//       derived from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
// ARE DISCLAIMED. IN NO EVENT SHALL COMPUTER CONSULTANCY PTY LTD BE LIABLE 
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
// DAMAGE.

using System;
using System.Collections.Generic;
using System.Text;

#endregion

namespace Interlace.Pinch.Dom
{
    public class Versioning
    {
        readonly int _addedInVersion;
        readonly int? _removedInVersion;

        public Versioning(int addedInVersion)
        {
            _addedInVersion = addedInVersion;
        }

        public Versioning(int addedInVersion, int removedInVersion)
        {
            _addedInVersion = addedInVersion;
            _removedInVersion = removedInVersion;
        }

        public static Versioning WithRemovedInVersion(Versioning versioning, int removedInVersion)
        {
            return new Versioning(versioning.AddedInVersion, removedInVersion);
        }

        public bool WasRemovedBeforeAdded
        {
            get
            {
                return _removedInVersion.HasValue && _removedInVersion <= _addedInVersion;
            }
        }

        public bool HasZeroVersionNumber
        {
            get 
            { 
                return _addedInVersion == 0 || (_removedInVersion.HasValue && _removedInVersion.Value == 0); 
            }
        }

        public int AddedInVersion
        { 	 
            get { return _addedInVersion; }
        }

        public int? RemovedInVersion
        { 	 
            get { return _removedInVersion; }
        }
        
        public int LatestReferencedVersion
        {
            get 
            {
                if (_removedInVersion.HasValue) return Math.Max(_addedInVersion, _addedInVersion);

                return _addedInVersion;
            }
        }
    }
}
